1. Field of the Invention
The embodiments herein generally relate to medical devices, and, more particularly, to medical devices used in spinal surgeries.
2. Description of the Related Art
Most conventional surgical drill guides generally do not offer various depth and positive settings to control accurate drilling depth. Threaded mechanisms within conventional drill guides are generally not positive due to the fact that rotary drills tend to destabilize or change the preset depth in the threaded adjustable depth drill guides. Other systems such as the one described in U.S. patent application Ser. No. 2003/0233098 A1, the complete disclosure of which in its entirety is herein incorporated by reference generally offer variable depth guides, but they are generally expensive and complicated to use, as well as possibly prone to failure due to fatigue because they typically depend on a spring portion that loses elasticity during normal use and hot steam autoclaving cycles that are necessary for cleaning surgical tools. Without a positive safe variable depth drill guide, one has to significantly increase drill bit inventory of multiple drill lengths to accomplish the same task. Other conventional designs generally incorporate too many parts such as multiple inner tubes with one or more outer tubes to provide a variety of depth.
Generally, the conventional drill guides may have the following attributes: (1) generally are less than positive designs; (2) generally are difficult to set depth and usage may require two hands; (3) typically the depth control is effected by a rotary drill or tool, making them potentially dangerous; (4) generally tend to rely on visual markings for depth as opposed to a firm stop to control depth; (5) generally require a multitude of inner tubes and/or drills to accomplish accurate depth drilling; and (6) typically tend to drill too deep in the human spine, which may cause death or severe nerve injury to the patient. Therefore, there remains a need for a novel variable depth drill guide capable of controlling the depth of drilling during spinal surgeries and which generally overcomes the limitations of the conventional drill guides.